Ecodan PUZ-WM85
The most-installed heat pump in the UK. Not the most efficient on paper; but with a near-unmatched track record of running reliably for a decade in real British homes.
- SCOP (35°C)
- 4.55
- Running cost
- £1,290/yr
- Installed
- £10,500–£13,500 installed (before grant)
Editorial render. Not a manufacturer photograph; we do not redistribute press imagery without a licence.
Primary question · Which heat pump has the most field data behind it in the UK?
Anyone prioritising service-network depth and the comfort of choosing the unit half the industry has actually lived with.
£10,500–£13,500 installed (before grant)
- Largest UK installer base
- Proven reliability
- Honest, conservative engineering
- R32 refrigerant is being phased down
- Top-end efficiency lags newer R290 units
Open the cost planner to estimate your installed price.
Key specifications
- Output
- 8.5 kW @ A7/W35
- SCOP (35°C)
- 4.55
- SCOP (55°C)
- 3.20
- Sound at 1 m
- 45 dB(A) max
- Refrigerant
- R32
- , Largest UK installer base
- , Proven reliability
- , Honest, conservative engineering
- , R32 refrigerant is being phased down
- , Top-end efficiency lags newer R290 units
Vaillant★★★★★aroTHERM plus 7 kW- SCOP (35°C)
- 5.05
- Running cost
- £1,180/yr
1970s–2000s 3-bedWell-insulated semisQuiet neighbourhoodsReadHouse Verdict9.3/10
Daikin★★★★★Altherma 3 H HT R290 (6 kW)- SCOP (35°C)
- 4.85
- Running cost
- £1,380/yr
Solid-wall VictoriansEdwardian terracesHigh-flow retrofitsReadHouse Verdict8.7/10
If your brief matches "anyone prioritising service-network depth and the comfort of choosing the unit half the industry has actually lived with.", the Ecodan PUZ-WM85 is a confident pick. If it doesn't, the alternatives above are more honest answers.
Estimate your installed cost
The planner uses your specific home; not a brochure number.